Fermi estimate with sampling and votes

from swarms import TreeOfThoughts

agent = TreeOfThoughts(
    name="Fermi-Estimator",
    model_name="gpt-5.4",
    search_algorithm="bfs",
    generation_strategy="sample",
    evaluation_strategy="vote",
    num_thoughts=3,
    breadth=2,
    max_depth=4,
    n_evaluate_samples=3,
    thought_description=(
        "One estimation step: a single quantity with a stated, justified "
        "assumption (for example the number of cars moving, a typical "
        "mass, a typical speed), or a combination of earlier quantities."
    ),
    evaluation_criteria=(
        "Prefer realistic, explicitly justified assumptions, correct "
        "arithmetic and units, and steady progress toward one number in "
        "joules."
    ),
)

answer = agent.run(
    "Estimate, to an order of magnitude, the total kinetic energy in "
    "joules of all cars moving on United States roads during a weekday "
    "rush hour. State your assumptions."
)
print(f"Answer: {answer}\n")

result = agent.last_result
for number, step in enumerate(result.steps, 1):
    print(f"{number}. {step}")
print(
    f"\nsolved={result.solved} nodes_expanded={result.nodes_expanded} "
    f"llm_calls={result.llm_calls} tokens={result.usage['total_tokens']}"
)